<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
     <!--样式-->
    <style type="text/css">
        div{
            width: 100px;
            height: 100px;
            background-color: green;
            margin-top: 20px;
            display: none;
        }
    </style>

</head>
<body>
    <!--body标签-->
    <button>操作</button>
    <div></div>
    <div></div>
    <div></div>
</body>
<script src="jquery.3.4.1.js"></script>
<script>
    // var btn = document.getElementsByTagName('button')[0]
    // btn.onclick = function () {
    //     var arr_div = document.getElementsByTagName('div')
    //     for(var index in arr_div){
    //         arr_div[index].innerText='神仙姐姐'
    //         arr_div[index].style.display = 'block'
    //     }
    // }

    $('button').click(function () {
        $('div').show().text('神仙姐姐')
    })

</script>
</html>